Beauty is but skin deep.

Physical attractiveness is an outward quality, not a measure of whether someone is kind, honest, or worthy of trust.

The proverb encourages judging people by their character and actions instead of treating an appealing appearance as proof of deeper virtues.

Use it to challenge an assumption that someone’s looks reveal their character, or to encourage attention to how a person behaves. Directed at a particular person, it may sound like a slight against their appearance.